Add documentation for Latch

[wout]

After reviewing, the luckyframework/lucky#2016 PR will be ready. I'll probably add more features later, but it's a big enough PR as it is. Once that's merged I'll start working on the documentation for it. This is an overview of the sections that need to be documented (also open for suggestions of course).

• Configuration
  • Setting up Memory and File stores in development
  • Setting up S3 stores for production
  • Using File stores in production
  • Path prefixes
• Uploaders
  • Configuring an uploader
  • Extending the StoredFile class
• Extractors
  • Using extractors
  • Creating simple extractors
  • Creating extractors with CLI dependencies
• Setup
  • Setting up the Model
  • Setting up the SaveOperation
  • Using file validations
  • How a DeleteOperation handles uploads
• Uploads in pages
  • Rendering uploaded files
  • File uploads in forms
  • Deleting uploaded files
  • Presigned URLs with S3 stores

This will be a complete rewrite of the Uploading Files section.

Thinking about it, if writing this section would help with getting a clear view on the totality of the luckyframework/lucky#2016 PR, I'd be happy to work on it first.

[wout]

I've already added all documentation in the README: https://github.com/wout/latch. I'll write the docs here based on that, but more from a Lucky/Avram perspective.

[jwoertink]

Yeah, we have file upload docs here https://luckyframework.org/guides/handling-files/file-uploads#setup but I think we can just swap it all out from Shrine to Latch since the last Shrine update was 4 years ago.